Water and Sediment Quantity and Quality Generated in Check Dams as a Nature-Based Solutions (NbS)

The study evaluates the implementation of check dams as nature-based solutions to address soil erosion, improve sediment quality, and enhance water retention in the Urku Huayku ravine, located on the Ilaló volcano in Ecuador. Weekly water and sediment samples were analysed from 2021 to 2023 to measure critical parameters such as pH, electrical conductivity, nutrient concentrations, and organic matter content. Macroinvertebrates were also collected to assess biodiversity changes, using indices like the Andean Biotic Index (ABI) and the Shannon Diversity Index. Results show significant improvements: water quality remained neutral (average pH 7.06), while sediment organic matter increased substantially from 0.2% in 2021 to 3.2% in 2023. Additionally, biodiversity improved, with a 355.6% increase in macroinvertebrate abundance. Statistical tests confirmed the positive impact of check dams on sediment and water quality. The study also identified potential areas for additional check dam installations using QGIS analysis, emphasising steep slopes as ideal locations. This work demonstrates the effectiveness of check dams in restoring degraded ecosystems and highlights their role in climate change mitigation through enhanced sediment carbon storage and improved biodiversity. Further research is recommended to optimise dam placement and explore additional biodiversity indicators.